11g, good for 6v (31 oz-in!) and tight, strong gear train. I have run a few of them on a 2cell LiFe pack but nobody recommends that. I think the resin gear train in the HS-81 is weak relative to its rating. It weighs about 50% more than the HS65HB, but has about 33% more torque. The 65 already has more torque than any 1/2A needs unless you make stiff linkages, which isn't the servo's fault.